Simple state machine

from perseus.state_machine.StateMachine import StateMachine

...

simple_path = Path(("A", None), ("B", None), ("C", ["FINISHED_PROJECT"]))
simple_state_machine = StateMachine(simple_path)

simple_state_machine.current_states()  # will return ["A"]
simple_state_machine.add_event(Event("A", None))  # state A fires event with no content
simple_state_machine.current_states()  # will return ["B"]
simple_state_machine.add_event(Event("B", None))  # state B fires event with no content
simple_state_machine.current_states()  # will return ["B"] because C requires the event value "FINISHED_PROJECT"
simple_state_machine.add_event(
    Event("B", "FINISHED_PROJECT")
)  # state B fires event with value "FINISHED_PROJECT"
simple_state_machine.current_states()  # will return ["C"]

This state machine consists of a defined path made up of three states: A, B, and C. Each step in the path can require a specific event value to trigger the transition to the next state.

In this example:

The state machine starts at state A.
The transition from A to B occurs when an event from A with no value is fired.
To move from B to C, an event from B with the value FINISHED_PROJECT must be fired. If the event from B has no value, the state machine stays in B.
Once the correct event is received, the state transitions to C.

Simple state machine

Graphical representation